Seismic analysis of the Roman Temple of Évora, Portugal

The Roman temple of Évora dates back to the 1st century AD and has undergone several changes throughout history, including various additions, which have been removed. Several archaeological studies have recently been carried out, but the structural safety of the temple is unknown. Of particular concern is the temple’s seismic resistance, as it is located in a region subjected to a moderate seismic hazard. The main purpose of this paper is to ascertain the temple’s behaviour under seismic excitation through limit analysis and discrete element analysis. Both analysis techniques will use the assumption that the structure is composed of rigid blocks connected with dry joints. Geometric information has been derived from a recent laser scanning surveying, while calibration undertaken using in-situ results from GPR and dynamic identification tests. The main results are presented and discussed in detail as well as the need for possible repair works within the framework of the ICARSAH guidelines

A New Tau Method for Solving Nonlinear Lane-Emden Type Equations via Bernoulli Operational Matrix of Differentiation

A new and efficient numerical approach is developed for solving nonlinear Lane-Emden type equations via Bernoulli operational matrix of differentiation. The fundamental structure of the presented method is based on the Tau method together with the Bernoulli polynomial approximations in which a new operational matrix is introduced. After implementation of our scheme, the main problem would be transformed into a system of algebraic equations such that its solutions are the unknown Bernoulli coefficients. Also, under several mild conditions the error analysis of the proposed method is provided. Several examples are included to illustrate the efficiency and accuracy of the proposed technique and also the results are compared with the different methods. All calculations are done in Maple 13

External review of the storage plan for the Peterhead Carbon Capture and Storage Project

This document summarises the findings of an external independent review of the storage plan for the proposed Peterhead Carbon Capture and Storage project which aims to store up to 20 million tonnes (Mt) of CO2 within the framework of the European Directive on the geological storage of CO2. The Peterhead Carbon Capture and Storage Project proposes to capture carbon dioxide (CO2) from an existing gas-fired power-station at Peterhead and to store this in geological strata at a depth of around 2600 m beneath the outer Moray Firth. The plan is to store 10 - 15 Mt of CO2 over a ten to fifteen-year period commencing around 2020, but the site is being qualified for 20 Mt to allow for potential extension of the injection period. Storage will utilise the depleted Goldeneye gas condensate field with the Captain Sandstone reservoir as the primary storage container. The Storage Site covers some 70 km2, and comprises the Captain Sandstone and underlying strata of the Cromer Knoll Group, bounded by a polygon some 2 to 3 km outside of the original Goldeneye oil-water contact. The Storage Complex is larger, around 154 km2, bounded some 2 to 7 km outside of the original oil-water contact, and extending upwards to the top of the Dornoch Mudstone at a depth of more than 800 m. The top-seal of the primary container is a proven caprock for natural gas and is formed by the mudstones of the Upper Cromer Knoll Group, the overlying Rødby and Hidra formations and the Plenus Marl. A number of additional seals are present in the overburden within the Storage Complex, as are a number of potential secondary containers which could also serve as monitoring horizons. The geological interpretation of the storage site is based on the comprehensive datasets acquired during the discovery, appraisal and development of the Goldeneye field, and also data from other wells, fields and seismic surveys in the surrounding area. The static geological model of the storage site and adjacent aquifer has been stress tested for the key uncertainties, and it is considered to be robust. The storage capacity of the Goldeneye structure has been calculated using both static (volumetric) methods and dynamic flow modelling together with uncertainty analysis. Total estimated capacity of the structural closure is in the range 25 to 47 Mt and so robustly exceeds the proposed injected amount

Conversion of organic matter in the carbonaceous medium in the supercritical water

© 2017 Elsevier B.V. The work is based on the modeling of geothermal transformations of hydrocarbons in oil-bearing formations of deep horizons of the earth's crust - under abnormally high pressure, in the presence of aqueous fluid and carbonaceous substances. The pressure and temperature in the experiments are typical for water in the supercritical state. The regularities of the conversion of heavy oil in supercritical water and in the presence of finely dispersed caustobioliths and metal oxides were shown. Aquathermolysis in the presence of proton provides blockage of free radicals of high-molecular weight hydrocarbons and saturation of unsaturated hydrocarbons, produced by cracking reactions, and inhibiting of condensation reactions of aromatic macromolecules. The hydrogen protons also promote hydrogenation reactions in the crude oil. The regularities of changes of the component, structural-group, fractional and elemental compositions of heavy oil during the conversion under the above conditions were established, rheological characteristics of the initial crude oil and converted oil were studied as well. As a result of carrying out aquathermolysis in the supercritical water environment and in the presence of initiating additives, the high-molecular weight components of the initial crude oil were degraded with the formation of light distillate fractions, which were scarcely present in the initial crude oil. Thus, the conversion rate for various samples amounted to 18–29%. It resulted in the significant reduction in the viscosity of the converted oil, up to 96% compared to the initial crude oil

Equilibrium conditions for semi-clathrate hydrates formed with CO2, N2 or CH4 in the presence of tri-n-butylphosphine oxide

We measured the thermodynamic stability conditions for the N, CO, or CH semiclathrate hydrate formed from the aqueous solution of tri-n-butylphosphine oxide (TBPO) at 26 wt %, corresponding to the stoichiometric composition for TBPO·34.5HO. The measurements were performed in the temperature range 283.71-300.34 K and pressure range 0.35-19.43 MPa with the use of an isochoric equilibrium step-heating pressure-search method. The results showed that the presence of TBPO made these semiclathrate hydrates much more stable than the corresponding pure N , CO, and CH hydrates. At a given temperature, the semiclathrate hydrate of 26 wt % TBPO solution + CH was more stable than that of 26 wt % TBPO solution + CO, which in turn was more stable than that of 26 wt % TBPO solution + N. We analyzed the phase equilibrium data using the Clausius-Clapeyron equation and found that, in the pressure range 0-20 MPa, the mean dissociation enthalpies for the semiclathrate hydrate systems of 26 wt % TBPO solution + N, 26 wt % TBPO solution + CO, and 26 wt % TBPO solution + CH were 177.75, 206.23, and 159.00 kJ·mol, respectively

Metabolic syndrome is linked to a mild elevation in liver aminotransferases in diabetic patients with undetectable non-alcoholic fatty liver disease by ultrasound

<p>Abstract</p> <p>Background</p> <p>Despite ongoing findings on the relationship between elevated levels of alanine and aspartate aminotransferases (ALT and AST) and metabolic syndrome (MetS), this association in diabetic patients without a known cause for liver enzymes elevation other than diabetes, per se, remains unclear. In this study, we aimed to assess the relationship between circulating liver enzymes and MetS in a relatively large sample of patients with diabetes.</p> <p>Methods</p> <p>A total of 670 diabetic patients, without known causes of hepatocellular injury, were enrolled. Patients with ultrasonographic signs of fatty liver disease were not included. Fasting blood samples were obtained and biochemical characteristics were measured. MetS was defined according to the international diabetes federation criteria.</p> <p>Results</p> <p>Serum ALT and AST were significantly higher in patients with MetS (p < 0.001). High waist circumference and low HDL-cholesterol were significantly associated with elevated ALT (OR = 2.56 and 2.0, respectively) and AST (OR = 2.23 and 2.21, respectively). ALT and AST were significantly associated with MetS (OR = 2.17 and 2.31, respectively). These associations remained significant after multiple adjustments for age, sex, BMI, diabetes duration, HbA1c and medications. There was a significant (p < 0.01) positive association between the number of the MetS features and the level of ALT or AST.</p> <p>Conclusion</p> <p>In diabetic patients without ultrasonographic evidence of fatty liver, elevated aminotransferases are independently associated with MetS. Despite negative ultrasound results in diabetic patients with MetS, the serum level of liver aminotransferases may be elevated and should be more thoroughly monitored.</p